The present invention relates to an accumulator used for storing a liquid under pressure and absorbing pulsation and other purposes, and particularly to an apparatus for supporting the diaphragm of an accumulator which is capable of preventing any damage to the outer periphery of a flange for fixing the diaphragm.
When a diaphragm is supported by the container body of an accumulator, a support ring having an inner edge in the form of a circular arc and a linear outer edge is generally fitted into a U-shaped groove provided in the outer periphery of the flange, and the support ring and the diaphragm are together fitted into the body of the container so that the outer edge of the support ring is engaged with a step portion of the container body (refer to Japanese Utility Model Laid-Open No. 164602/1988 and U.S. Pat. No. 4793381).
A conventional apparatus for supporting the diaphragm of an accumulator comprises a support ring 13 which is formed by bending a sheet metal or machining a round slice of a pipe into the form shown in FIG. 6. However, since the support ring 13 is formed so as to have a diameter which is smaller than that of a container body 14 by a margin which allows engagement therewith, a gap 15 is produced between the container body 14 and the outer periphery of the support ring 13 when the support ring is fitted into the container body 14, as shown the same drawing. An outer peripheral portion 17a of the flange 17 of a diaphragm 16 is placed close above the gap 15 and enters the gap 15 during pressurization and returns during pressure reduction. There is thus a problem in that, if these actions are repeated, the outer peripheral portion 17a of the flange 17 is flawed, and the flaw thus produced is gradually increased by repetition of the pressing and pressure reduction in the accumulator, finally leading to damage of the outer peripheral portion 17a of the flange.